por cpl em 25/09/17, atualizado em 04/01/14

D-Series Block Posting

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(D-Series Block Posting)

Block "posting" is a method of reinforcing an open deck block to make the sleeves less susceptible to cracking/breaking due to stress caused by high RPM and/or high cylinder pressures (boost). A common method of reinforcing cylinders is by the use of a blockguard. When properly installed, a blockguard has proven successful for many people. The key word there is properly. Most good blockguards are machined to fit your block, welded in, and then a bore/hone job is required to true everything back up. Additionally, the "good" blockguards have generous room for cooling. The "hammer it in" style blockguard has been the culprit in many blockguard related horror stories. Do it right, or don't do it all! Your typical blockguard reinforces the cylinders only at the top of the deck.

Posting reinforces the cylinder at 12 strategic points where side load is very high. For the garage mechanic, this method is actually easier (IMO) and will significantly increase the strength of an open deck block. 12 aluminum threaded posts are screwed into the block to reinforce the sleeves where they need it the most.

Finally, a bore/hone job is in order to make sure everything runs true. The stock sleeves are apparently accurate to .0001", so installing anything that touches them (posts or a blockguard) requires boring/honing to true everything up.



1) exhaust side measurements: 1.50" down from the deck, centered on axis with each cylinder
Intake side measurements: top pin at 0.90" and bottom pin at 2.10" down from the deck, centered on axis with each cylinder

2) carbide grind approximately 1 square inch of the surface around where the hole locations will be, to rough it up enough to get rid of any oxidation on the aluminum and for the aluminum epoxy to adhere better

3) use a 5/16" drill bit and a 3/8 - 16 tap size

4) thoroughly clean the pins, holes, and roughed surfaces with acetone and allow to dry

5) Place a little aluminum epoxy on the threads of the pins as well as the holes and work the epoxy in by screwing the pin in and out a couple times

6) screw in pins to cylinder walls to 2 pounds and cover (both front and back) with enough epoxy to cover all of the exposed pin and the adjacent roughed block wall

7) let fully cure to time instructed, as per the epoxy used